package com.example.demo.utils;

import javax.servlet.http.HttpServletRequest;

public class IPUtils {
	/** 
	     * 获取用户真实IP地址，不使用request.getRemoteAddr()的原因是有可能用户使用了代理软件方式避免真实IP地址, 
	     * 可是，如果通过了多级反向代理的话，X-Forwarded-For的值并不止一个，而是一串IP值 
	     *  
	     * @return ip
	     */
		public static String getIpAddr(HttpServletRequest request) {
	        String ip = request.getHeader("x-forwarded-for"); 
	        if (ip != null && ip.length() != 0 && !"unknown".equalsIgnoreCase(ip)) {  
	            // 多次反向代理后会有多个ip值，第一个ip才是真实ip
	            if( ip.indexOf(",")!=-1 ){
	                ip = ip.split(",")[0];
	            }
	        }  
	        if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {  
	            ip = request.getHeader("Proxy-Client-IP");  
	        }  
	        if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {  
	            ip = request.getHeader("WL-Proxy-Client-IP");  
	        }  
	        if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {  
	            ip = request.getHeader("HTTP_CLIENT_IP");  
	        }  
	        if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {  
	            ip = request.getHeader("HTTP_X_FORWARDED_FOR");  
	        }  
	        if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {  
	            ip = request.getHeader("X-Real-IP");  
	        }  
	        if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {  
	            ip = request.getRemoteAddr();  
	        } 
	        return ip;  
	    }
}

